如何在networkx中从字典中创建有向图？

import networkx as nx

# 创建一个空的有向图
G = nx.DiGraph()

# 定义一个字典，键为节点，值为边的权重
edges = {
    'A': {'B': 1, 'C': 2},
    'B': {'C': 3},
    'C': {'A': 4}
}

# 遍历字典，将节点和边添加到有向图中
for node, neighbors in edges.items():
    for neighbor, weight in neighbors.items():
        G.add_edge(node, neighbor, weight=weight)

# 打印有向图的节点和边
print("节点：", G.nodes())
print("边：", G.edges(data=True))